#include <stdio.h>
#include <unistd.h>

void func(){
    int aa = 10;
    int bb = 20;
    int cc = 30;
}

struct Data{
    int a_;
    int b_;
};

int main(){
    int* a = NULL;
    *a = 10;

#if 0
    int a = 10;
    int b = 20;
    int c = a + b;

    func();

    struct Data dd;
    dd.a_ = 100;
    dd.b_ = 200;

    struct Data* lp = &dd;
    lp->a_ = 1000;
    lp->b_ = 2000;

    printf("c = %d\n", c);
#endif
    return 0;
}
